X 1. (convention) Used in various speech and writing contexts (also in lowercase) in roughly its algebraic sense of "unknown within a set defined by context" (compare N). Thus, the abbreviation 680x0 stands for 68000, 68010, 68020, 68030 or 68040, and 80x86 stands for Intel 80186, Intel 80286, Intel 80386 or Intel 80486. A Unix hacker might write these as 680[0-4]0 and 80[1-4]86 or 680?0 and 80?86 respectively; see glob.
2. (graphics) An alternative name for the X Window System. 3. (storage) A suffix for the speed of a CD-ROM drive relative to standard music CDs (1x). 32x is common in September 1999. [Jargon File] Last updated: 1999-09-15
